A comparative study of the effects of the Hofmeister series anions of the ionic salts and ionic liquids on the stability of α-chymotrypsin

2015 ◽  
Vol 39 (2) ◽  
pp. 938-952 ◽  
Author(s):  
Awanish Kumar ◽  
Anjeeta Rani ◽  
Pannuru Venkatesu
Keyword(s):  
Ionic Liquids ◽  
Amino Acid ◽  
Comparative Study ◽  
Hofmeister Series ◽  
Amino Acid Residues ◽  
Ionic Salts ◽  
The Stability ◽  
Catalytic Amino Acid

Direct interactions between the anion and the catalytic amino acid residues lead to denaturation of CT.

scholarly journals Synthesis and Evaluation of Cyclic Acetals of Serine Hydroxylamine for Amide-Forming KAHA Ligations

Synthesis ◽  
2019 ◽  
Vol 51 (05) ◽  
pp. 1273-1283 ◽  
Author(s):  
Simon Baldauf ◽  
Jeffrey Bode
Keyword(s):  
Amino Acid ◽  
Amino Acid Residue ◽  
Amino Acid Residues ◽  
High Demand ◽  
Cyclic Acetals ◽  
Ligation Product ◽  
Canonical Amino Acid ◽  
The Stability ◽  
Peptide Segments ◽  
Derivatives Of

The α-ketoacid–hydroxylamine (KAHA) ligation allows the coupling of unprotected peptide segments. The most widely used variant employs a 5-membered cyclic hydroxylamine that forms a homoserine ester as the primary ligation product. While very effective, monomers that give canonical amino acid residues are in high demand. In order to preserve the stability and reactivity of cyclic hydroxylamines, but form a canonical amino acid residue upon ligation, we sought to prepare cyclic derivatives of serine hydroxylamine. An evaluation of several cyclization strategies led to cyclobutanone ketals as the leading structures. The preparation, stability, and amide-forming ligation of these serine-derived ketals are described.

A comparative study of the stability of stem bromelain based on the variation of anions of imidazolium-based ionic liquids

2017 ◽  
Vol 246 ◽  
pp. 178-186 ◽  
Author(s):  
Pannuru Kiran Kumar ◽  
Indrani Jha ◽  
Pannuru Venkatesu ◽  
Indra Bahadur ◽  
Eno E. Ebenso
Keyword(s):  
Ionic Liquids ◽  
Comparative Study ◽  
Stem Bromelain ◽  
The Stability

Enhanced stability of Cu2+–ATCUN complexes under physiologically relevant conditions by insertion of structurally bulky and hydrophobic amino acid residues into the ATCUN motif

2016 ◽  
Vol 45 (23) ◽  
pp. 9436-9445 ◽  
Author(s):  
Takaaki Miyamoto ◽  
Yuta Fukino ◽  
Shinichiro Kamino ◽  
Masashi Ueda ◽  
Shuichi Enomoto
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Hydrophobic Amino Acid ◽  
Hydrophobic Residues ◽  
The Stability ◽  
Enhanced Stability

The stability of Cu2+–ATCUN complexes under physiologically relevant conditions is enhanced by inserting bulky and hydrophobic residues at positions 1 and 2 of the ATCUN peptide.

Structure - function analysis of photosystem II subunit S (PsbS) in vivo

2002 ◽  
Vol 29 (10) ◽  
pp. 1131 ◽  
Author(s):  
Xiao-Ping Li ◽  
Alba Phippard ◽  
Jae Pasari ◽  
Krishna K. Niyogi
Keyword(s):  
Amino Acid ◽  
Photosystem Ii ◽  
Function Analysis ◽  
Amino Acid Sequences ◽  
Forward Genetics ◽  
Photochemical Quenching ◽  
Amino Acid Residues ◽  
The Stability ◽  
Psbs Gene

In land plants, photosystem II subunit S (PsbS) plays a key role in xanthophyll- and pH-dependent non-photochemical quenching (qE) of excess absorbed light energy. Arabidopsis thaliana (L.) Heynh. npq4 mutants are defective in the psbS gene and have impaired qE. Exactly how the PsbS protein is involved in qE is unclear, but it has been proposed that PsbS binds H+ and/or de-epoxidized xanthophylls in excess light as part of the qE mechanism. To identify amino acid residues that are important for PsbS function, we sequenced the psbS gene from eight npq4 point mutant alleles isolated by forward genetics screening, including two new alleles. In the four transmembrane helices of PsbS, several amino acid residues were found to affect the stability and/or function of the protein. By comparing the predicted amino acid sequences of PsbS from several plant species and studying the proposed topological structure of PsbS, eight possible H+-binding amino acid residues on the lumenal side of the protein were identified and then altered by site-directed mutagenesis in vitro. The mutant psbS genes were transformed into npq4-1, a psbS deletion mutant, to test the stability and function of the mutant PsbS proteins in�vivo. The results demonstrate that two conserved, protonatable amino acids, E122 and E226, are especially critical for the function of PsbS.

Identification of Catalytic Amino Acid Residues by Chemical Modification in Dextranase

2016 ◽  
Vol 26 (5) ◽  
pp. 837-845 ◽  
Author(s):  
Jin-A Ko ◽  
Seung-Hee Nam ◽  
Doman Kim ◽  
Jun-Ho Lee ◽  
Young-Min Kim
Keyword(s):  
Amino Acid ◽  
Chemical Modification ◽  
Amino Acid Residues ◽  
Catalytic Amino Acid

scholarly journals Homology Modeling and Prediction of Catalytic Amino Acid in the Neurotoxin from Indian Cobra (Naja naja)

2008 ◽  
Vol 2 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Pallavi Somvanshi ◽  
Vijai Singh
Keyword(s):  
Amino Acid ◽  
Homology Modeling ◽  
Active Site ◽  
3D Structure ◽  
Nerve Impulse ◽  
Amino Acid Residues ◽  
Small Peptide ◽  
Naja Naja ◽  
Modeling And Prediction ◽  
Catalytic Amino Acid

The neurotoxin secreted by Indian cobra (Naja naja) binds to acetylcholine receptor of nerve cells, which leads to a lump in the nerve impulse, ceases breathing, thereby causing the death of a person due to suffocation. These neurotoxins are small peptide with approximately 7 kDa. Homology modeling was performed to generate the 3D structure of neurotoxins (A, B, C and D) of N. naja, using the known protein template crystal structure (PDB: 2CTX). The validation of 3D structure was done using PROCHECK. Furthermore, the prediction of catalytic amino acid residues in the active site domain of the 3-D structure of neurotoxin was identified. The 3-D structures of neurotoxin and catalytic amino acid residue may be used to target and design the antivenom drugs against the Indian cobra.

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